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  1. MariaDB Server
  2. MDEV-36338

vector search with Cosine Distance is slow

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Duplicate
    • None
    • N/A
    • Vector search
    • None

    Description

      run ann-benchmarks with nytimes-256-angular is slow.
      cpu perf pic is attached
      pstack pic is attached show PatternedSimdBloomFilter size is too large

      Attachments

        1. m1.jpg
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        2. m2.jpg
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        Issue Links

          blocks

          New Feature - A new feature of the product, which has yet to be developed. MDEV-33408 HNSW for k-ANN vector searches

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed
          duplicates

          Bug - A problem which impairs or prevents the functions of the product. MDEV-35897 Questions about memory allocation done for vector index search

          • Major - Major loss of function.
          • Open

          Activity

            Ascending order - Click to sort in descending order
            myx myx added a comment - - edited

            we should reset ef_power = 0.6 in MHNSW_Share::acquire

            diff --git a/sql/vector_mhnsw.cc b/sql/vector_mhnsw.cc
            		 
            index d8a63a7558c..14eec69bbd2 100644
            		 
            --- a/sql/vector_mhnsw.cc
            		 
            +++ b/sql/vector_mhnsw.cc
            		 
            @@ -715,7 +715,7 @@ int MHNSW_Share::acquire(MHNSW_Share **ctx, TABLE *table, bool for_update)
            		 
                 if (table->file->has_transactions())
            		 
                   mysql_rwlock_rdlock(&(*ctx)->commit_lock);
            		 
               }
            		 
            -
            		 
            +  (*ctx)->ef_power = 0.6;
            		 
               if ((*ctx)->start)
            		 
                 return 0;

            myx myx added a comment - - edited we should reset ef_power = 0.6 in MHNSW_Share::acquire diff --git a/sql/vector_mhnsw.cc b/sql/vector_mhnsw.cc index d8a63a7558c..14eec69bbd2 100644 --- a/sql/vector_mhnsw.cc +++ b/sql/vector_mhnsw.cc @@ - 715 , 7 + 715 , 7 @@ int MHNSW_Share::acquire(MHNSW_Share **ctx, TABLE *table, bool for_update) if (table->file->has_transactions()) mysql_rwlock_rdlock(&(*ctx)->commit_lock); } - + (*ctx)->ef_power = 0.6 ; if ((*ctx)->start) return 0 ;
            myx myx added a comment -

            ctx->diameter also need reset in MHNSW_Share::acquire

            myx myx added a comment - ctx->diameter also need reset in MHNSW_Share::acquire
            serg Sergei Golubchik added a comment -

            ctx->diameter must not be reset, it's the largest distance between any two vectors in the index.

            The bloom filter size is far from optimal, indeed. It will be fixed in MDEV-35897

            serg Sergei Golubchik added a comment - ctx->diameter must not be reset, it's the largest distance between any two vectors in the index. The bloom filter size is far from optimal, indeed. It will be fixed in MDEV-35897

            People

              Unassigned Unassigned
              myx myx
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              Dates

                Created:
                Updated:
                Resolved:

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